不同环境和不同生长年限下野生和栽培甘草的微进化研究

Microevolution is the source of the biodiversity, which focuses on genetic evolution speed and mechanism of the same species, and their influence on the change of species’ properties. Study on the correlation and difference of gene and second metabolite between wild and cultivated traditional Chinese medicine (TCM) belong to the category of microevolution. At present, natural TCM distribution and storage is shrinking. For the sustainable utilization of natural TCM, culture was introduced. From the perspective of microevolution, secondary metabolism of cultural TCM is the results of the adaptation and selection of the original plant to external environmental during the evolutionary process, and the secondary metabolites are regulated by the gene. However, how TCM original plant adapt to the different environment, how genetic variations occur and how to regulate the secondary metabolites, the principle is not very clear. For answer above questions, this project intends to select licorice as the research object, an important TCM with clear cultivation history and variable secondary metabolites under different conditions, to investigate the difference of functional gene and secondary metabolites between cultural and wild licorice and establish microevolution model. This project also explores the effect on genetic variation direction and speed by environment choice, and influence on propertie and secondary metabolites of licorice by genetic variation.

微进化是生物多样性的来源，着重于研究同一物种基因进化速度和机制、进而对性状变化的影响。微进化具有普适性，野生与栽培中药的基因及次级代谢产物的关联与差异研究也可归属于此范畴。目前，我国野生中药分布范围和贮藏量日益缩减，为保持中药资源的可持续性利用，许多需求量大的药材须依靠栽培。从微进化角度出发，栽培中药的次生代谢产物是其在进化过程中对外界环境变异适应和选择的结果，而次生代谢产物的种类和含量受基因调控。然中药原植物如何适应不同环境，产生基因变异，导致次级代谢产物种类和含量变化的原理并不十分清楚，从而导致中药栽培缺少深入的理论指导。为阐明上述问题，本项目拟选取栽培史可考察、已知次级代谢产物受环境影响明显的常用中药甘草为研究对象，考察栽培和野生甘草在功能基因及次级代谢产物之间的关联和差异，建立甘草微进化模型，探讨环境选择对基因变异方向和速度的作用，以及基因变异对甘草原植物性状和次生代谢产物的影响。

甘草作为重要的药用植物广泛使用，其药效很大程度上依赖于甘草苷和甘草酸。为了探索野生和栽培甘草不同药效的基因调控模式，我们收集了野生，栽培一年和三年的甘草根样本以及根际土壤样本，通过HPLC分析和测序获得了上述样本的次级代谢产物含量、转录组数据、以及根际微生物组数据，并进行了全面的多组学分析。我们重构了甘草中所有40,091个基因的基因结构，新增了1,052个新基因的注释信息，绘制了包含52个差异表达基因的甘草苷和甘草酸生物合成的通路图，其中基因BAS、CYP72A154和CYP88D6对甘草酸的生物合成至关重要。多组学网络分析确定了溶菌杆菌与CYP72A154密切相关，这对甘草酸生物合成至关重要。此外，构建了一个整体的多组学调控模型，在此基础上确认根际微生物群落结构对甘草苷的积累至关重要。本项目研究彻底破译了甘草苷和甘草酸的关键调控途径，为植物关键代谢物与其转录组、根际微生物和环境的相互作用提供了广阔的视野，对指导甘草的栽培具有重要意义。